Results. Two-step GMM estimates of simultaneous equations. Dependent variable: Income.

From left to right, the number of control variables, which are listed on the left, increases in a stepwise fashion. The IVs for disease are variables that are in the disease equation (listed in the corresponding columns in Table 5) but not in the income equation here. Robust standard errors are presented in parentheses next to their corresponding coefficient estimates. First-stage F-test indicates strength of IVs if there is only one endogenous variable (disease). If there are multiple endogenous variables (disease, institutions, and spatially lagged income), Shea's partial R2 indicates strength of IVs [75]. Bold indicates significance at the 10% level. n = 139. IVVariable is instrumented. JBased on Hansen's J statistic. aUnits×10−2. *p≤0.10. **p≤0.05. ***p≤0.01.